In some situations it is required to pick up soil at one location and transport it to another. In the case of road building for instance, the contour of the ground is changed to form a road by taking the soil from one location and placing it in another. Not only must the soil be removed from one location, it must also be placed in another specific location.
In many situations however, it is only desired to remove the soil from its current location, and the location it is moved to is not critical. Often it is desired to simply spread the removed soil so that it does not interfere with future operations on the land. An example is where ditches are made to drain standing water from ponds on agricultural lands.
Conventional soil moving machines include scrapers and loaders, where a generally horizontal blade is moved at a shallow depth along the ground, lifting soil and moving same into a bucket where it remains until dumped. Scrapers may incorporate a chain elevator to assist in moving the soil into the bucket. Trenchers or ditchers generally move the soil from the trench and pile it beside the trench, although ditchers are also known which spread the soil that is removed. Such soil-spreading ditchers are disclosed in U.S. Pat. Nos. 3,624,826 to Rogers, U.S. Pat. No. 5,237,761 to Nadeau et al., U.S. Pat. No. 5,113,610 to Liebrecht et al., and U.S. Pat. No. 6,226,903B1 to Erickson.
The ditch cleaning apparatus of Rogers comprises a disc rotating in a substantially vertical plane. The apparatus rides on skids and is designed essentially to clean existing ditches. The ditcher of Nadeau et al. similarly comprises a disc rotating in a substantially vertical plane and having rippers ahead of the disc. The disc of Nadeau et al. disperses the soil loosened by the rippers. The apparatuses of Rogers and Nadeau et al. leave a ditch with a rounded bottom having a radius substantially equal to the radius of the disc.
The apparatus of Liebrecht et al., U.S. Pat. No. 5,113,610, uses a spinning disc to both cut and spread the soil. The plane of the disc is oriented at a shallow angle of 15-30 degrees above horizontal, and a shallow angle to one side of 10-30 degrees.
The apparatus of Erickson, U.S. Pat. No. 6,226,903, uses a blade to scrape up soil and deposit it onto a spinning disc that has a plane oriented at less than 45 degrees above horizontal. The blade raises the soil onto a pan and then the soil passes over the pan and onto the disc which has an edge that is juxtaposed to a semi-circular cut-out in the pan. The disc rotates at a relatively shallow angle so that the soil is not raised very much before it is thrown off the disc. A beater may be provided above the pan to push the raised soil down onto the disc as it leaves the pan. The beater axis is upwardly and rearwardly of the leading edge of the cutting blade such that the beater serves only to direct the soil which is already flowing upwardly from the cutting blade, rearwardly towards the spinning disc.
U.S. Pat. No. 6,536,140 belonging to Vaags et at is another example of a soil spreading scraper including a blade to scrape up soil and a spinning disc for spreading the cut soil. A kicker supported for rotation about a horizontal axis ahead of the spinning disc assists in feeding cut soil to the spinning disc. The cutting blade is parallel to the rotation plane of the disc at a steep angle of near 75 degrees from horizontal such that the kicker is necessarily spaced well above the ground. Accordingly, similarly to Erickson noted above, the kicker serves only to direct the soil which is already flowing upwardly from the cutting blade, rearwardly towards the spinning disc.
U.S. Pat. No. 7,627,964 by Vaags et al is yet another example of a soil spreading scraper including a blade to scrape up soil, a spinning disc for spreading the cut soil, and a kicker ahead of the spinning disc to assist in feeding cut soil from the cutting blade to the spinning disc. Substantially the entire kicker is upwardly and rearwardly of the leading edge of the cutting blade such that the kicker serves only to direct the soil which is already flowing upwardly from the cutting blade, rearwardly towards the spinning disc.
Many of the ditcher implements noted above encounter problems of wear of the impeller blades on the spinning discs thereof. U.S. Pat. No. 5,190,140 by Buschbom discloses one example of liners on the leading faces of the impeller blades which can be replaced when worn. The impeller blades and the liners supported thereon must be rotated in close proximity to a peripheral wall of the chamber rotatably receiving the impeller blades therein for efficient operation, however, it can be difficult to manufacture the impeller blades with the degree of precision required for optimal efficiency.
Among the ditcher type implements noted above which include a kicker above the cutting blade, another problem which is encountered is the lodging of debris between the kicker and the cutting blade which prevents continued rotation of the kicker. Examples of reverser mechanisms for various implements are disclosed in U.S. Pat. No. 7,669,400 by Naaktgeboren, U.S. Pat. No. 6,681,552 by Nelson et al, and U.S. Pat. No. 3,608,557 by Evans; however, none of the prior art devices are suitably arranged for incorporation into a ditcher implement in a manner which readily permits maintenance as required.